Video surveillance footage from a department store near the finish line, was detailed by a city politician two days after the attack that left three people dead, wounded more than 170, and cast a dark shadow over one of this city’s most joyous traditions.

The footage has not been made public but the website 4chan Think Tank generated this “un-official” image of possible suspects fitting the profile.

Massachusetts Gov. Deval Patrick spoke on the frustration that the person or people responsible were still at large, but he said solving the case will not “happen by magic.”

“It’s going to happen by doing the careful work that must be done in a thorough investigation,” Patrick said. “That means going through the couple of blocks at the blast scene square inch by square inch and picking up pieces of evidence and following those trails, and that’s going to take some time.”